another twist to this, JP,....just my right speaker buzzes...pretty loud, swapped speaker leads stayed on the same channnel , annoying for sure.....so I just lifted the sound board off the backbox...the loud hum went away from the right speaker....and I now have both speakers buzzing about half as loud as when it was just one.......doing the plastic screws Mod and think about this some more.

B.

-a FYI, tip your board out and make sure the grounding is not showing on the back of the board, mine was so I stuck a nylon nut to insulate the board from making a ground contact on the backside.

try using a extension code and plugging into a for sure different power circuit in your house, maybe even a dedicated one from your panel, or try a small UPS, before you get to far into it.... mine was buzzing pretty bad in the shop/garage and after I moved it to the game room its gone...I did float the board as described in my post above.... had mine down to dull roar i could live with after shopping it, then bam gone on a different circuit.

peace, B.